Members of the Cotton family, which owned the majority of Meridian, were unavailable for comment Tuesday.

"WellCare and Meridian have a shared commitment to quality — with Meridian maintaining high quality and accredited Medicaid plans in both Michigan and Illinois," Burdick said. "We look forward to leveraging best practices across the entire company in order to improve quality for all of our members. We also want to welcome Meridian associates, members, agents, and providers to WellCare."

WellCare reported 4.3 million Medicaid members as of the first quarter of this year. It reported income of $373.7 million on $17 billion in revenue in 2017.

In a statement, WellCare said the transaction is expected to add 40 cents to 50 cents to WellCare's adjusted earnings per share in 2019. WellCare said it absorbed one-time transaction-related expenses of $75 million to $85 million and integration-related expenses of $50 million to $60 million.

Founded by David Cotton, M.D., and his wife, Shery, in 1997, Meridian is Michigan's largest Medicaid health plan, with more than 500,000 members, and was one of the largest family-owned for-profit managed-care companies in the nation. Overall, Meridian served about 1.1 million Medicaid, Medicare Advantage, integrated dual-eligible and health insurance marketplace members.

Meridian also a major employer in downtown Detroit and ranks fourth on Crain's Private 200 list of largest privately held companies in metro Detroit with $3.8 billion in 2017. The company has become a visible fixture in downtown Detroit since purchasing One Campus Martius with Dan Gilbert's Bedrock LLC in 2015 for an estimated $140 million to $150 million.